Colloidal nanoplatelets with two-dimensional electronic structure
Source abstract
Abstract
The syntheses of strongly anisotropic nanocrystals with one dimension much smaller than the two others, such as nanoplatelets, are still greatly underdeveloped. Here, we demonstrate the formation of atomically flat quasi-two-dimensional colloidal CdSe, CdS and CdTe nanoplatelets with well-defined thicknesses ranging from 4 to 11 monolayers. These nanoplatelets have the electronic properties of two-dimensional quantum wells formed by molecular beam epitaxy, and their thickness-dependent absorption and emission spectra are described very well within an eight-band Pidgeon-Brown model. They present an extremely narrow emission spectrum with full-width at half-maximum less than 40 meV at room temperature. The radiative fluorescent lifetime measured in CdSe nanoplatelets decreases with temperature, reaching 1 ns at 6 K, two orders of magnitude less than for spherical CdSe nanoparticles. This makes the nanoplatelets the fastest colloidal fluorescent emitters and strongly suggests that they show a giant oscillator strength transition.
Source: europepmc · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Quantum Dots Synthesis And Properties · Chalcogenide Semiconductor Thin Films · Nanocluster Synthesis and Applications
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (35)
Show source-provided references
1. Murray, C. B., Norris, D. J. & Bawendi, M. G. Synthesis and characterization of nearly monodisperse CdE (E=S, Se, Te) semiconductor nanocrystallites. J. Am. Chem. Soc. 115, 8706–8715 (1993).10.1021/ja00072a025 ↗
2. Manna, L., Milliron, D. J., Meisel, A., Scher, E. C. & Alivisatos, A. P. Controlled growth of tetrapod-branched inorganic nanocrystals. Nature Mater. 2, 382–385 (2003).10.1038/nmat902 ↗
3. Yin, Y. & Alivisatos, A. P. Colloidal nanocrystal synthesis and the organic–inorganic interface. Nature 437, 664–670 (2005).10.1038/nature04165 ↗
4. Peng, X. G. et al. Shape control of CdSe nanocrystals. Nature 404, 59–61 (2000).10.1038/35003535 ↗
5. Michalet, X. et al. Quantum dots for live cells, in vivo imaging, and diagnostics. Science 307, 538–544 (2005).10.1126/science.1104274 ↗
6. Mahler, B., Lequeux, N. & Dubertret, B. Ligand-controlled polytypism of thick-shell CdSe/CdS nanocrystals. J. Am. Chem. Soc. 132, 953–959 (2010).10.1021/ja9034973 ↗
7. Muljarov, E. A., Zhukov, E. A., Dneprovskii, V. S. & Masumoto, Y. Dielectrically enhanced excitons in semiconductor–insulator quantum wires: Theory and experiment. Phys. Rev. B 62, 7420–7432 (2000).10.1103/PhysRevB.62.7420 ↗
8. Mulyarov, E. A. & Tikhodeev, S. G. Dielectric enhancement of excitons in semiconducting quantum wires. J. Exp. Theor. Phys. 84, 151–155 (1997).10.1134/1.558144 ↗
9. Shabaev, A. & Efros, A. L. 1D exciton spectroscopy of semiconductor nanorods. Nano Lett. 4, 1821–1825 (2004).10.1021/nl049216f ↗
10. Bartnik, A. C., Efros, A. L., Koh, W. K., Murray, C. B. & Wise, F. W. Electronic states and optical properties of PbSe nanorods and nanowires. Phys. Rev. B 82, 195313 (2010).10.1103/PhysRevB.82.195313 ↗
11. Keldysh, L. V. Coulomb interaction in thin semiconductor and semimetal films. J. Exp Theor. Phys. Lett. 29, 658–661 (1979).
12. Gippius, N. A. et al. Excitons in near-surface quantum wells in magnetic fields: Experiment and theory. J. Appl. Phys. 83, 5410–5417 (1998).10.1063/1.367370 ↗
13. Tikhodeev, S. G. et al. Excitons in near surface quantum wells: Local probe of semiconductor/vacuum surface. Phys. Status Solidi 164, 179–182 (1997).10.1002/1521-396X(199711)164:1<179::AID-PSSA179>3.0.CO;2-9 ↗
14. Kulik, L. V. et al. Dielectric enhancement of excitons in near-surface quantum wells. Phys. Rev. B 54, R2335–R2338 (1996).10.1103/PhysRevB.54.R2335 ↗
15. Jackson, J. D. Classical Electrodynamics 3rd edn (Wiley, 1998).
16. Rashba, E. I. & Gurgenishvili, G. E. Edge absorption theory in semiconductors. Sov. Phys. Solid State 4, 759–760 (1962).
17. Feldmann, J. et al. Linewidth dependence of radiative exciton lifetimes in quantum-wells. Phys. Rev. Lett. 59, 2337–2340 (1987).10.1103/PhysRevLett.59.2337 ↗
18. Kan, C. X. et al. Gold microplates with well-defined shapes. Small 6, 1768–1775 (2010).10.1002/smll.201000600 ↗
19. Puntes, V. F., Zanchet, D., Erdonmez, C. K. & Alivisatos, A. P. Synthesis of hcp-Co nanodisks. J. Am. Chem. Soc. 124, 12874–12880 (2002).10.1021/ja027262g ↗
20. Huo, Z. Y. et al. Self-organized ultrathin oxide nanocrystals. Nano Lett. 9, 1260–1264 (2009).10.1021/nl900209w ↗
21. Yu, T., Lim, B. & Xia, Y. N. Aqueous-phase synthesis of single-crystal ceria nanosheets. Angew. Chem. Int. Ed. 49, 4484–4487 (2010).10.1002/anie.201001521 ↗
22. Ithurria, S. & Dubertret, B. Quasi 2D colloidal CdSe platelets with thicknesses controlled at the atomic level. J. Am. Chem. Soc. 130, 16504–16505 (2008).10.1021/ja807724e ↗
23. Joo, J., Son, J. S., Kwon, S. G., Yu, J. H. & Hyeon, T. Low-temperature solution-phase synthesis of quantum well structured CdSe nanoribbons. J. Am. Chem. Soc. 128, 5632–5633 (2006).10.1021/ja0601686 ↗
24. Son, J. S. et al. Large-scale soft colloidal template synthesis of 1.4 nm thick CdSe nanosheets. Angew. Chem. Int. Ed. 48, 6861–6864 (2009).10.1002/anie.200902791 ↗
25. Liu, Y. H., Wayman, V. L., Gibbons, P. C., Loomis, R. A. & Buhro, W. E. Origin of high photoluminescence efficiencies in CdSe quantum belts. Nano Lett. 10, 352–357 (2010).10.1021/nl903740p ↗
26. Ithurria, S., Bousquet, G. & Dubertret, B. Continuous transition from 3D to 1D confinement observed during the formation of CdSe nanoplatelets. J. Am. Chem. Soc. 133, 3070–3077 (2011).10.1021/ja110046d ↗
27. Schliehe, C. et al. Ultrathin PbS sheets by two-dimensional oriented attachment. Science 329, 550–553 (2010).10.1126/science.1188035 ↗
28. Ouyang, J. et al. Multiple families of magic-sized CdSe nanocrystals with strong bandgap photoluminescence via noninjection one-pot syntheses. J. Phys. Chem. C 112, 13805–13811 (2008).10.1021/jp803845n ↗
29. Li, Z. & Peng, X. G. Size/shape-controlled synthesis of colloidal CdSe quantum disks: Ligand and temperature effects. J. Am. Chem. Soc. 133, 6578–6586 (2011).10.1021/ja108145c ↗
30. Pidgeon, C. R. & Brown, R. N. Interband magneto-absorption and Faraday rotation in InSb. Phys. Rev. 146, 575–583 (1966).10.1103/PhysRev.146.575 ↗
31. Kohn, W. & Luttinger, J. M. Quantum theory of electrical transport phenomena. Phys. Rev. 108, 590–611 (1957).10.1103/PhysRev.108.590 ↗
32. Nirmal, M., Murray, C. B. & Bawendi, M. G. Fluorescence-line narrowing in Cdse quantum dots—surface localization of the photogenerated exciton. Phys. Rev. B 50, 2293–2300 (1994).10.1103/PhysRevB.50.2293 ↗
33. Donega, C. D., Bode, M. & Meijerink, A. Size- and temperature-dependence of exciton lifetimes in CdSe quantum dots. Phys. Rev. B 74, 085320 (2006).10.1103/PhysRevB.74.085320 ↗
34. Crooker, S. A., Barrick, T., Hollingsworth, J. A. & Klimov, V. I. Multiple temperature regimes of radiative decay in CdSe nanocrystal quantum dots: Intrinsic limits to the dark-exciton lifetime. Appl. Phys. Lett. 82, 2793–2795 (2003).10.1063/1.1570923 ↗
35. Hines, M. A. & Guyot-Sionnest, P. Synthesis and characterization of strongly luminescing ZnS-capped CdSe nanocrystals. J. Phys. Chem.—US 100, 468–471 (1996).10.1021/jp9530562 ↗